BACKGROUND & OBJECTIVES: Intertrochanteric fractures of femur is one of the most common fractures of the hip especially in elderly, accounting for 10 to 34% of all hip fractures. By 2040, the incidence is estimated to be doubled. Surgical stabilization of these fractures remains a challenge. Dissatisfaction with extra medullary devices especially in unstable fractures, led to the evolution of intramedullary devices. So the Proximal femoral nail was designed which gives an advantage of intramedullary device. This study analyses the radiological and functional outcome of treatment of intertrochanteric fractures with Proximal Femoral Nail. METHODS: This study is a prospective, time bound, hospital based study conducted in KEMPEGOWDA INSTITUTE OF MEDICAL SCIENCES AND RESEARCH CENTER, Bangalore, between November 2012 to May 2014. The study included 40 cases of intertrochanteric fractures that were operated with the proximal femoral nail. The fractures were classified according to AO/ASIF classification and were followed up at regular intervals. Clinical and radiological parameters including Tip-apex distance, position of tip of Lag screw in femoral head as well as lateral slide of lag screw were noted. Final functional outcome was assessed using Kyle's criteria. RESULTS: Good reduction was achieved in 90% of the cases. 65% had ideal placement of lag screw in femoral head (Inferior on AP view and central on LATERAL view). Intra-operative difficulties were encountered in 20% of the cases. Mean TADAP was 11.92 mm, TADLAT was 11.50mm and mean TADTOTAL was found to be 23.42mm. All but one fracture united on an average in 17.74 weeks. Overall mean average slide was 3 mm and it was more in unstable fracture. We had three cases (7.5%) of mechanical failure, one case (2.5%) of Z effect without screw cut through. 80% patients returned to pre-injury levels of activity with 87.50% patients had good to excellent outcome as per Kyle's criteria. CONCLUSION: Proximal Femoral Nail provides good fixation for unstable intertrochanteric fractures, if proper preoperative planning, good reduction and surgical technique are followed, leading to high rate of bone union and minimal soft tissue damage. Proper reduction and placement of the screws are absolutely essential for successful fixation. Optimal position of lag screw is inferior on AP view and central on Lateral view. Tip apex distance should be kept to minimum, especially its AP component. The lag screw should be inserted deeply into the femoral head, close to sub chondral bone. Anti-rotation screw should be 10-15mm shorter than the lag screw.